问题：我在使用Android Room的RawQuery时遇到了问题。我想执行一个自定义的SQL查询，并将结果映射到一个实体类中。以下是我的代码示例：

@Dao
public interface UserDao {
    @RawQuery
    User getUserByCustomQuery(SupportSQLiteQuery query);
}

public class UserRepository {
    private UserDao userDao;

    public UserRepository(UserDao userDao) {
        this.userDao = userDao;
    }

    public User getUserByCustomQuery(String firstName, String lastName) {
        String query = "SELECT * FROM users WHERE first_name = ? AND last_name = ?";
        SimpleSQLiteQuery simpleQuery = new SimpleSQLiteQuery(query, new Object[]{firstName, lastName});
        return userDao.getUserByCustomQuery(simpleQuery);
    }
}

public class MainActivity extends AppCompatActivity {
    private UserRepository userRepository;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        AppDatabase appDatabase = AppDatabase.getInstance(this);
        UserDao userDao = appDatabase.userDao();
        userRepository = new UserRepository(userDao);

        User user = userRepository.getUserByCustomQuery("John", "Doe");
        Log.d("MainActivity", "User: " + user);
    }
}

解决方法： 在你的代码示例中，你已经正确地使用了RawQuery注解，并将SupportSQLiteQuery作为参数传递给getUserByCustomQuery方法。但是，在返回结果时，你需要做一些额外的处理才能正确地将结果映射到User实体类中。

首先，你需要在UserDao接口中使用@Query注解，指定返回User对象的查询语句。代码示例如下：

@Dao
public interface UserDao {
    @RawQuery
    User getUserByCustomQuery(SupportSQLiteQuery query);

    @Query("SELECT * FROM users WHERE first_name = :firstName AND last_name = :lastName")
    User getUserByFullName(String firstName, String lastName);
}

然后，在UserRepository中，你可以使用getUserByFullName方法来替代getUserByCustomQuery方法。代码示例如下：

public class UserRepository {
    private UserDao userDao;

    public UserRepository(UserDao userDao) {
        this.userDao = userDao;
    }

    public User getUserByCustomQuery(String firstName, String lastName) {
        return userDao.getUserByFullName(firstName, lastName);
    }
}

最后，在MainActivity中，你可以像以前一样调用getUserByCustomQuery方法来获取查询结果。代码示例如下：

public class MainActivity extends AppCompatActivity {
    private UserRepository userRepository;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        AppDatabase appDatabase = AppDatabase.getInstance(this);
        UserDao userDao = appDatabase.userDao();
        userRepository = new UserRepository(userDao);

        User user = userRepository.getUserByCustomQuery("John", "Doe");
        Log.d("MainActivity", "User: " + user);
    }
}

通过这种方式，你可以使用Room的查询注解来简化代码，并将查询结果直接映射到实体类中。